The drift layer of a super junction semiconductor device typically includes n-doped and p-doped columns. A high impurity concentration in the n-doped columns results in a low on-state resistance of the semiconductor device. On the other hand, when a reverse voltage is applied, depletion zones extend between the n-doped columns and the p-doped columns in a lateral direction such that a high reverse breakdown voltage can be achieved despite the high impurity concentration in the n-doped columns. It is desirable to improve the forward and reverse characteristics of super junction semiconductor devices.